/*
 * Copyright C 2003 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 */
package java.io;

/**
 * This abstract class is the superclass of all classes representing an output
 * stream of bytes. An output stream accepts output bytes and sends them to some
 * sink.
 * <p>
 * Applications that need to define a subclass of <code>OutputStream</code> must
 * always provide at least a method that writes one byte of output.
 *
 * @author Arthur van Hoff
 * @version 12/17/01 (CLDC 1.1)
 * @see java.io.ByteArrayOutputStream
 * @see java.io.DataOutputStream
 * @see java.io.InputStream
 * @see java.io.OutputStream#write(int)
 * @since JDK1.0, CLDC 1.0
 */
public abstract class OutputStream implements Closeable, Flushable {

    /**
     * Writes the specified byte to this output stream. The general contract for
     * <code>write</code> is that one byte is written to the output stream. The
     * byte to be written is the eight low-order bits of the argument
     * <code>b</code>. The 24 high-order bits of <code>b</code> are ignored.
     * <p>
     * Subclasses of <code>OutputStream</code> must provide an implementation
     * for this method.
     *
     * @param b the <code>byte</code>.
     * @exception IOException if an I/O error occurs. In particular, an
     * <code>IOException</code> may be thrown if the output stream has been
     * closed.
     */
    public abstract void write(int b) throws IOException;

    /**
     * Writes <code>b.length</code> bytes from the specified byte array to this
     * output stream. The general contract for <code>write(b)</code> is that it
     * should have exactly the same effect as the call
     * <code>write(b, 0, b.length)</code>.
     *
     * @param b the data.
     * @exception IOException if an I/O error occurs.
     * @see java.io.OutputStream#write(byte[], int, int)
     */
    public void write(byte b[]) throws IOException {
        write(b, 0, b.length);
    }

    /**
     * Writes <code>len</code> bytes from the specified byte array starting at
     * offset <code>off</code> to this output stream. The general contract for
     * <code>write(b, off, len)</code> is that some of the bytes in the array
     * <code>b</code> are written to the output stream in order; element
     * <code>b[off]</code> is the first byte written and
     * <code>b[off+len-1]</code> is the last byte written by this operation.
     * <p>
     * The <code>write</code> method of <code>OutputStream</code> calls the
     * write method of one argument on each of the bytes to be written out.
     * Subclasses are encouraged to override this method and provide a more
     * efficient implementation.
     * <p>
     * If <code>b</code> is <code>null</code>, a
     * <code>NullPointerException</code> is thrown.
     * <p>
     * If <code>off</code> is negative, or <code>len</code> is negative, or
     * <code>off+len</code> is greater than the length of the array
     * <code>b</code>, then an <tt>IndexOutOfBoundsException</tt> is thrown.
     *
     * @param b the data.
     * @param off the start offset in the data.
     * @param len the number of bytes to write.
     * @exception IOException if an I/O error occurs. In particular, an
     * <code>IOException</code> is thrown if the output stream is closed.
     */
    public void write(byte b[], int off, int len) throws IOException {
        if (b == null) {
            throw new NullPointerException();
        } else if ((off < 0) || (off > b.length) || (len < 0)
                || ((off + len) > b.length) || ((off + len) < 0)) {
            throw new IndexOutOfBoundsException();
        } else if (len == 0) {
            return;
        }
        for (int i = 0; i < len; i++) {
            write(b[off + i]);
        }
    }

    /**
     * Flushes this output stream and forces any buffered output bytes to be
     * written out. The general contract of <code>flush</code> is that calling
     * it is an indication that, if any bytes previously written have been
     * buffered by the implementation of the output stream, such bytes should
     * immediately be written to their intended destination.
     * <p>
     * The <code>flush</code> method of <code>OutputStream</code> does nothing.
     *
     * @exception IOException if an I/O error occurs.
     */
    public void flush() throws IOException {
    }

    /**
     * Closes this output stream and releases any system resources associated
     * with this stream. The general contract of <code>close</code> is that it
     * closes the output stream. A closed stream cannot perform output
     * operations and cannot be reopened.
     * <p>
     * The <code>close</code> method of <code>OutputStream</code> does nothing.
     *
     * @exception IOException if an I/O error occurs.
     */
    public void close() throws IOException {
    }

}
